151 resultados para Fashion blogs
Resumo:
Telomerase is a ribonucleoprotein complex responsible for the maintenance of the length of the telomeres during cell division, which is active in germ-line cells as well as in the vast majority of tumors but not in most normal tissues. The wide expression of the human telomerase catalytic subunit (hTERT) in tumors makes it an interesting candidate vaccine for cancer. hTERT-derived peptide 540-548 (hTERT(540)) has been recently shown to be recognized in an HLA-A*0201-restricted fashion by T cell lines derived from peptide-stimulated peripheral blood mononuclear cells (PBMC) from healthy donors. As a first step to the inclusion of this peptide in immunotherapy clinical trials, it is crucial to assess hTERT(540)-specific T cell reactivity in cancer patients as well as the ability of hTERT-specific CD8(+) T lymphocytes to recognize and lyse hTERT-expressing target cells. Here, we have analyzed the CD8(+) T cell response to peptide hTERT(540) in HLA-A*0201 melanoma patients by using fluorescent HLA-A*0201/hTERT(540) peptide tetramers. HLA-A*0201/hTERT(540) tetramer(+) CD8(+) T cells were readily detected in peptide-stimulated PBMC from a significant proportion of patients and could be isolated by tetramer-guided cell sorting. hTERT(540)-specific CD8(+) T cells were able to specifically recognize HLA-A*0201 cells either pulsed with peptide or transiently transfected with a minigene encoding the minimal epitope. In contrast, they failed to recognize hTERT-expressing HLA-A*0201(+) target cells. Furthermore, in vitro proteasome digestion studies revealed inadequate hTERT processing. Altogether, these results raise questions on the use of hTERT(540) peptide for cancer immunotherapy.
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PURPOSE: Repeated-sprint training in hypoxia (RSH) was recently shown to improve repeated-sprint ability (RSA) in cycling. This phenomenon is likely to reflect fiber type-dependent, compensatory vasodilation, and therefore, our hypothesis was that RSH is even more beneficial for activities involving upper body muscles, such as double poling during cross-country skiing. METHODS: In a double-blinded fashion, 17 competitive cross-country skiers performed six sessions of repeated sprints (each consisting of four sets of five 10-s sprints, with 20-s intervals of recovery) either in normoxia (RSN, 300 m; FiO2, 20.9%; n = 8) or normobaric hypoxia (RSH, 3000 m; FiO2, 13.8 %; n = 9). Before (pre) and after (post) training, performance was evaluated with an RSA test (10-s all-out sprints-20-s recovery, until peak power output declined by 30%) and a simulated team sprint (team sprint, 3 × 3-min all-out with 3-min rest) on a double-poling ergometer. Triceps brachii oxygenation was measured by near-infrared spectroscopy. RESULTS: From pretraining to posttraining, peak power output in the RSA was increased (P < 0.01) to the same extent (29% ± 13% vs 26% ± 18%, nonsignificant) in RSH and in RSN whereas the number of sprints performed was enhanced in RSH (10.9 ± 5.2 vs 17.1 ± 6.8, P < 0.01) but not in RSN (11.6 ± 5.3 vs 11.7 ± 4.3, nonsignificant). In addition, the amplitude in total hemoglobin variations during sprints throughout RSA rose more in RSH (P < 0.01). Similarly, the average power output during all team sprints improved by 11% ± 9% in RSH and 15% ± 7% in RSN. CONCLUSIONS: Our findings reveal greater improvement in the performance of repeated double-poling sprints, together with larger variations in the perfusion of upper body muscles in RSH compared with those in RSN.
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PURPOSE: To analyze outcomes after right portal vein embolization extended to segment IV (right PVE + IV) before extended right hepatectomy, including liver hypertrophy, resection rates, and complications after embolization and resection, and to assess differences in outcomes with two different particulate embolic agents. MATERIALS AND METHODS: Between 1998 and 2004, transhepatic ipsilateral right PVE + IV with particles and coils was performed in 44 patients with malignant hepatobiliary disease, including metastases (n = 24), biliary cancer (n = 14), and hepatocellular carcinoma (n = 6). Right PVE + IV was considered if the future liver remnant (FLR; segments II/III with or without I) was less than 25% of the total estimated liver volume (TELV). Tris-acryl microspheres (100-700 microm; n = 21) or polyvinyl alcohol (PVA) particles (355-1,000 microm; n = 23) were administered in a stepwise fashion. Smaller particles were used to occlude distal branches, followed by larger particles to occlude proximal branches until near-complete stasis. Coils were then placed in secondary portal branches. Computed tomographic volumetry was performed before and 3-4 weeks after right PVE + IV to assess FLR hypertrophy. Liver volumes and postembolization and postoperative outcomes were measured. RESULTS: After right PVE + IV with PVA particles, FLR volume increased 45.5% +/- 40.9% and FLR/TELV ratio increased 6.9% +/- 5.6%. After right PVE + IV with tris-acryl microspheres, FLR volume increased 69.0% +/- 30.7% and FLR/TELV ratio increased 9.7% +/- 3.3%. Differences in FLR volume (P = .0011), FLR/TELV ratio (P = .027), and resection rates (P = .02) were statistically significant. Seventy-one percent of patients underwent extended right hepatectomy (86% after receiving tris-acryl microspheres, 57% after receiving PVA). Thirteen patients (29%) did not undergo resection (extrahepatic spread [n = 9], inadequate hypertrophy [n = 3], other reasons [n = 1]). No patient developed postembolization syndrome or progressive liver insufficiency after embolization or resection. One death after resection occurred as a result of sepsis and hemorrhage. Median hospital stays were 1 day after right PVE + IV and 7 days after resection. CONCLUSION: Transhepatic ipsilateral right PVE + IV with use of particles and coils is a safe, effective method for inducing contralateral hypertrophy before extended right hepatectomy. Embolization with small spherical particles provides improved hypertrophy and resection rates compared with larger, nonspherical particles.
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OBJECTIVES: During open heart surgery, so-called atrial chatter, a phenomenon due to right atria and/or caval collapse, is frequently observed. Collapse of the cava axis during cardiopulmonary bypass (CPB) limits venous drainage and may result downstream in reduced pump flow on (lack of volume) and upstream in increased after-load (stagnation), which in turn may both result in reduced or even inadequate end-organ perfusion. The goal of this study was to reproduce venous collapse in the flow bench. METHODS: In accordance with literature for venous anatomy, a caval tree system is designed (polyethylene, thickness 0.061 mm), which receives venous inflow from nine afferent veins. With water as medium and a preload of 4.4 mmHg, the system has an outflow of 4500 ml/min (Scenario A). After the insertion of a percutaneous venous cannula (23-Fr), the venous model is continuously served by the afferent branches in a venous test bench and venous drainage is augmented with a centrifugal pump (Scenario B). RESULTS: With gravity drainage (siphon: A), spontaneously reversible atrial chatter can be generated in reproducible fashion. Slight reduction in the outflow diameter allows for generation of continuous flow. With augmentation (B), irreversible collapse of the artificial vena cava occurs in reproducible fashion at a given pump speed of 2300 ± 50 RPM and a pump inlet pressure of -112 mmHg. Furthermore, bubbles form at the cannula tip despite the fact that the entire system is immersed in water and air from the environment cannot enter the system. This phenomenon is also known as cavitation and should be avoided because of local damage of both formed blood elements and endothelium, as well embolization. CONCLUSIONS: This caval model provides a realistic picture for the limitations of flow due to spontaneously reversible atrial chatter vs irreversible venous collapse for a given negative pressure during CPB. Temporary interruption of negative pressure in the venous line can allow for recovery of venous drainage. This know-how can be used not only for testing different cannula designs, but also for further optimizing perfusion strategies.
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The purpose of this study was to assess the inhibitory effect of TCV-116, an orally active angiotensin II (Ang II) antagonist, on the pressor action of exogenous Ang II and to determine the compensatory rise in plasma renin activity and Ang II levels. Twenty-three male volunteers were treated for 8 days in a double-blind fashion with either placebo or TCV-116 (1, 2, or 4 mg PO daily) and challenged on the first, fourth, and eighth days with repeated bolus injections of Ang II. An additional 4 subjects received 8 mg PO daily in a single-blind fashion. The inhibitory effect on the systolic blood pressure response to Ang II was long lasting and clearly dose related. Six hours after 4 mg TCV-116, the systolic blood pressure response to a given dose of Ang II was reduced to 40 +/- 4% and 35 +/- 8% of baseline value on days 1 and 8, respectively. TCV-116 induced a dose-related increase in plasma renin activity and Ang II levels that was more pronounced on the eighth than on the first day of drug administration. Despite this compensatory mechanism, the relation between the time-integrated systolic blood pressure response to Ang II and the time-integrated CV-11974 levels, the active metabolite of TCV-116, was not different between days 1 and 8. In conclusion, TCV-116 appears to be a well-tolerated, orally active, potent, and long-lasting antagonist of Ang II in men.
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We study an adaptive statistical approach to analyze brain networks represented by brain connection matrices of interregional connectivity (connectomes). Our approach is at a middle level between a global analysis and single connections analysis by considering subnetworks of the global brain network. These subnetworks represent either the inter-connectivity between two brain anatomical regions or by the intra-connectivity within the same brain anatomical region. An appropriate summary statistic, that characterizes a meaningful feature of the subnetwork, is evaluated. Based on this summary statistic, a statistical test is performed to derive the corresponding p-value. The reformulation of the problem in this way reduces the number of statistical tests in an orderly fashion based on our understanding of the problem. Considering the global testing problem, the p-values are corrected to control the rate of false discoveries. Finally, the procedure is followed by a local investigation within the significant subnetworks. We contrast this strategy with the one based on the individual measures in terms of power. We show that this strategy has a great potential, in particular in cases where the subnetworks are well defined and the summary statistics are properly chosen. As an application example, we compare structural brain connection matrices of two groups of subjects with a 22q11.2 deletion syndrome, distinguished by their IQ scores.
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Since the 1980s in Western Europe, centralized states' control over subnational territories has been deeply affected by processes of Europeanization and regionalization. These changes have raised the issue of state territorial restructuring in a particular fashion: what capacity have formerly centralized states retained to steer and control subnational territories? The article draws on Mann's concept of infrastructural power, which refers to the state's capacity to exercise control and implement political decisions over the national territory. The article applies the two main operationalizations of the concept, namely the capability of the state to exercise control and the weight of the state in the subnational territories. Empirically, the article focuses on the French state in two policy sectors (education and housing). Although France is a most likely case, this article challenges this expectation, and shows the limits of the French state's infrastructural power over the subnational territories since the late 1980s.
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In this paper, I reframe the long-standing controversy between 'psychological egoism', which argues that human beings never perform altruistic actions, and the opposing thesis of 'psychological altruism', which claims that human beings are, at least sometimes, capable of acting in an altruistic fashion. After a brief sketch of the controversy, I begin by presenting some representative arguments in favour of psychological altruism before showing that they can all be called into question by appealing to the idea of an unconscious self-directed motive. I will then point out that this argumentative strategy not only debunks the reasons for favouring psychological altruism, but also those for favouring psychological egoism; hence it is no use in settling the dispute between the two views. In the second part of the paper, I will try to break this deadlock by reframing the whole controversy, shifting it away from the concept of motive, towards the broader notion of motivation. As it turns out, this shift enables the debate to centre on altruistic emotions and their motivational power, thereby allowing evolutionary arguments to enter the debate and settle the dispute in favour of psychological altruism.
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The SSX-2 gene encodes a tumor-specific antigen expressed in neoplasms of various histological types. By analyzing a tumor-infiltrated lymph node of a melanoma patient bearing an SSX-2-expressing tumor, we have recently identified the first SSX-2-derived CD8(+) T-cell epitope, that corresponds to peptide SSX-2(41-49), and is recognized by specific CTL in an HLA-A2 restricted fashion. Here, we have used fluorescent HLA-A2/SSX-2(41-49) peptide multimeric complexes to analyze the response to SSX-2(41-49) in melanoma patients and healthy donors. Multimer(+) CD8(+) T cells were readily detected in the majority of patients bearing SSX-2-expressing tumors and, at lower proportions, in patients with nonexpressing tumors and healthy donors. Importantly, isolated A2/SSX-2(41-49) multimer(+) CD8(+) T cells exhibited a large functional heterogeneity in terms of antigen recognition and tumor reactivity. SSX-2-specific CTLs isolated from tumor-infiltrated lymph node of antigen-expressing patients as well as from the corresponding peripheral blood mononuclear cells exhibited high functional avidity of antigen recognition and efficiently recognized antigen-expressing tumors. In contrast, SSX-2-specific CTLs isolated from patients with undetectable responses in the tumor-infiltrated lymph node, as well as from healthy donors, recognized the antigen with decreased functional avidity and were not tumor reactive. Together, these data indicate that CD8(+) T-cell responses to SSX-2(41-49) frequently occur in SSX-2-expressing melanoma patients and suggest that SSX-2(41-49)-specific CTLs of high avidity and tumor reactivity are selectively expanded during immune responses to SSX-2-expressing tumors in vivo.
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BACKGROUND: Maintaining therapeutic concentrations of drugs with a narrow therapeutic window is a complex task. Several computer systems have been designed to help doctors determine optimum drug dosage. Significant improvements in health care could be achieved if computer advice improved health outcomes and could be implemented in routine practice in a cost effective fashion. This is an updated version of an earlier Cochrane systematic review, by Walton et al, published in 2001. OBJECTIVES: To assess whether computerised advice on drug dosage has beneficial effects on the process or outcome of health care. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care Group specialized register (June 1996 to December 2006), MEDLINE (1966 to December 2006), EMBASE (1980 to December 2006), hand searched the journal Therapeutic Drug Monitoring (1979 to March 2007) and the Journal of the American Medical Informatics Association (1996 to March 2007) as well as reference lists from primary articles. SELECTION CRITERIA: Randomized controlled trials, controlled trials, controlled before and after studies and interrupted time series analyses of computerized advice on drug dosage were included. The participants were health professionals responsible for patient care. The outcomes were: any objectively measured change in the behaviour of the health care provider (such as changes in the dose of drug used); any change in the health of patients resulting from computerized advice (such as adverse reactions to drugs). DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed study quality. MAIN RESULTS: Twenty-six comparisons (23 articles) were included (as compared to fifteen comparisons in the original review) including a wide range of drugs in inpatient and outpatient settings. Interventions usually targeted doctors although some studies attempted to influence prescriptions by pharmacists and nurses. Although all studies used reliable outcome measures, their quality was generally low. Computerized advice for drug dosage gave significant benefits by:1.increasing the initial dose (standardised mean difference 1.12, 95% CI 0.33 to 1.92)2.increasing serum concentrations (standradised mean difference 1.12, 95% CI 0.43 to 1.82)3.reducing the time to therapeutic stabilisation (standardised mean difference -0.55, 95%CI -1.03 to -0.08)4.reducing the risk of toxic drug level (rate ratio 0.45, 95% CI 0.30 to 0.70)5.reducing the length of hospital stay (standardised mean difference -0.35, 95% CI -0.52 to -0.17). AUTHORS' CONCLUSIONS: This review suggests that computerized advice for drug dosage has some benefits: it increased the initial dose of drug, increased serum drug concentrations and led to a more rapid therapeutic control. It also reduced the risk of toxic drug levels and the length of time spent in the hospital. However, it had no effect on adverse reactions. In addition, there was no evidence to suggest that some decision support technical features (such as its integration into a computer physician order entry system) or aspects of organization of care (such as the setting) could optimise the effect of computerised advice.
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The large spatial inhomogeneity in transmit B(1) field (B(1)(+)) observable in human MR images at high static magnetic fields (B(0)) severely impairs image quality. To overcome this effect in brain T(1)-weighted images, the MPRAGE sequence was modified to generate two different images at different inversion times, MP2RAGE. By combining the two images in a novel fashion, it was possible to create T(1)-weighted images where the result image was free of proton density contrast, T(2) contrast, reception bias field, and, to first order, transmit field inhomogeneity. MP2RAGE sequence parameters were optimized using Bloch equations to maximize contrast-to-noise ratio per unit of time between brain tissues and minimize the effect of B(1)(+) variations through space. Images of high anatomical quality and excellent brain tissue differentiation suitable for applications such as segmentation and voxel-based morphometry were obtained at 3 and 7 T. From such T(1)-weighted images, acquired within 12 min, high-resolution 3D T(1) maps were routinely calculated at 7 T with sub-millimeter voxel resolution (0.65-0.85 mm isotropic). T(1) maps were validated in phantom experiments. In humans, the T(1) values obtained at 7 T were 1.15+/-0.06 s for white matter (WM) and 1.92+/-0.16 s for grey matter (GM), in good agreement with literature values obtained at lower spatial resolution. At 3 T, where whole-brain acquisitions with 1 mm isotropic voxels were acquired in 8 min, the T(1) values obtained (0.81+/-0.03 s for WM and 1.35+/-0.05 for GM) were once again found to be in very good agreement with values in the literature.
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Paralysis with pancuronium bromide is used in newborn infants to facilitate ventilatory support during respiratory failure. Changes in lung mechanics have been attributed to paralysis. The aim of this study was to examine whether or not paralysis per se has an influence on the passive respiratory mechanics, resistance (Rrs) and compliance (Crs) of the respiratory system in newborn infants. In 30 infants with acute respiratory failure, Rrs was measured during paralysis with pancuronium bromide and after stopping pancuronium bromide (group A). Rrs was also measured in an additional 10 ventilated infants in a reversed fashion (group B): Rrs was measured first in nonparalysed infants and then they were paralysed, mainly for diagnostic procedures, and the Rrs measurement repeated. As Rrs is highly dependent on lung volume, several parameters, that depend directly on lung volume were recorded: inspiratory oxygen fraction (FI,O2), arterial oxygen tension/alveolar oxygen tension (a/A) ratio and volume above functional residual capacity (FRC). In group A, the Rrs was not different during (0.236+/-0.09 cmH2O x s x mL(-1)) and after (0.237+/-0.07 cmH2O x s x mL(-1)) paralysis. Also, in group B, Rrs did not change (0.207+/-0.046 versus 0.221+/-0.046 cm x s x mL(-1) without versus with pancuronium bromide). FI,O2, a/A ratio and volume above FRC remained constant during paralysis. These data demonstrate that paralysis does not influence the resistance of the total respiratory system in ventilated term and preterm infants when measured at comparable lung volumes.
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The human brainstem is a densely packed, complex but highly organised structure. It not only serves as a conduit for long projecting axons conveying motor and sensory information, but also is the location of multiple primary nuclei that control or modulate a vast array of functions, including homeostasis, consciousness, locomotion, and reflexive and emotive behaviours. Despite its importance, both in understanding normal brain function as well as neurodegenerative processes, it remains a sparsely studied structure in the neuroimaging literature. In part, this is due to the difficulties in imaging the internal architecture of the brainstem in vivo in a reliable and repeatable fashion. A modified multivariate mixture of Gaussians (mmMoG) was applied to the problem of multichannel tissue segmentation. By using quantitative magnetisation transfer and proton density maps acquired at 3 T with 0.8 mm isotropic resolution, tissue probability maps for four distinct tissue classes within the human brainstem were created. These were compared against an ex vivo fixated human brain, imaged at 0.5 mm, with excellent anatomical correspondence. These probability maps were used within SPM8 to create accurate individual subject segmentations, which were then used for further quantitative analysis. As an example, brainstem asymmetries were assessed across 34 right-handed individuals using voxel based morphometry (VBM) and tensor based morphometry (TBM), demonstrating highly significant differences within localised regions that corresponded to motor and vocalisation networks. This method may have important implications for future research into MRI biomarkers of pre-clinical neurodegenerative diseases such as Parkinson's disease.
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Ionotropic glutamate receptors (iGluRs) mediate neuronal communication at synapses throughout vertebrate and invertebrate nervous systems. We have characterized a family of iGluR-related genes in Drosophila, which we name ionotropic receptors (IRs). These receptors do not belong to the well-described kainate, AMPA, or NMDA classes of iGluRs, and they have divergent ligand-binding domains that lack their characteristic glutamate-interacting residues. IRs are expressed in a combinatorial fashion in sensory neurons that respond to many distinct odors but do not express either insect odorant receptors (ORs) or gustatory receptors (GRs). IR proteins accumulate in sensory dendrites and not at synapses. Misexpression of IRs in different olfactory neurons is sufficient to confer ectopic odor responsiveness. Together, these results lead us to propose that the IRs comprise a novel family of chemosensory receptors. Conservation of IR/iGluR-related proteins in bacteria, plants, and animals suggests that this receptor family represents an evolutionarily ancient mechanism for sensing both internal and external chemical cues.
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PURPOSE: To report feasibility and potential benefits of high-frequency jet ventilation (HFJV) in tumor ablations techniques in liver, kidney, and lung lesions. METHODS: This prospective study included 51 patients (14 women, mean age 66 years) bearing 66 tumors (56 hepatic, 5 pulmonary, 5 renal tumors) with a median size of 16 ± 8.7 mm, referred for tumor ablation in an intention-to-treat fashion before preoperative anesthesiology visit. Cancellation and complications of HFJV were prospectively recorded. Anesthesia and procedure duration, as well as mean CO2 capnea, were recorded. When computed tomography guidance was used, 3D spacial coordinates of an anatomical target <2 mm in diameter on 8 slabs of 4 slices of 3.75-mm slice thickness were registered. RESULTS: HFJV was used in 41 of 51 patients. Of the ten patients who were not candidate for HFJV, two patients had contraindication to HFJV (severe COPD), three had lesions invisible under HFJV requiring deep inspiration apnea for tumor targeting, and five patients could not have HFJV because of unavailability of a trained anesthetic team. No specific complication or hypercapnia related to HFJV were observed despite a mean anesthetic duration of 2 h and ventilation performed in procubitus (n = 4) or lateral decubitus (n = 6). Measured internal target movement was 0.3 mm in x- and y-axis and below the slice thickness of 3.75 mm in the z-axis in 11 patients. CONCLUSIONS: HFJV is feasible in 80 % of patients allowing for near immobility of internal organs during liver, kidney, and lung tumor ablation.